In Northern California, the ground has slipped back into one of its most unnerving habits: a burst of small quakes that seem to come out of nowhere and refuse to stop. The latest swarm centered near ...

A swarm of a half-dozen earthquakes reaching up to magnitude 2.9 rattled San Ramon in California near San Francisco, the U.S. Geological Survey reports. The other quakes in Saturday's swarm ranged ...

A 4.4 magnitude earthquake struck near Willits in Mendocino County on Tuesday afternoon. The quake was reported at 1:10 p.m. about 5 miles east-southeast of Willits and about 17 miles north of Ukiah.

An earthquake swarm is a series of small quakes that “may occur in a region for months without a major earthquake,” according to Britannica.. Getty Images/iStockphoto A swarm of a half-dozen ...